In order for computational fluid dynamics to provide quantitative parameters to aid in the clinical assessment of type B aortic dissection, the results must accurately mimic the hemodynamic environment within the aorta. The choice of inlet velocity profile (IVP) therefore is crucial; however, idealised profiles are often adopted, and the effect of IVP on hemodynamics in a dissected aorta is unclear. This study examined two scenarios with respect to the influence of IVP—using (a) patient-specific data in the form of a three-directional (3D), through-plane (TP) or flat IVP; and (b) non-patient-specific flow waveform. The results obtained from nine simulations using patient-specific data showed that all forms of IVP were able to reproduce global flow patterns as observed with 4D flow magnetic resonance imaging. Differences in maximum velocity and time-averaged wall shear stress near the primary entry tear were up to 3% and 6%, respectively, while pressure differences across the true and false lumen differed by up to 6%. More notable variations were found in regions of low wall shear stress when the primary entry tear was close to the left subclavian artery. The results obtained with non-patient-specific waveforms were markedly different. Throughout the aorta, a 25% reduction in stroke volume resulted in up to 28% and 35% reduction in velocity and wall shear stress, respectively, while the shape of flow waveform had a profound influence on the predicted pressure. The results of this study suggest that 3D, TP and flat IVPs all yield reasonably similar velocity and time-averaged wall shear stress results, but TP IVPs should be used where possible for better prediction of pressure. In the absence of patient-specific velocity data, effort should be made to acquire patient’s stroke volume and adjust the applied IVP accordingly.

为了让计算流体动力学提供定量参数以帮助 B 型主动脉夹层的临床评估，结果必须准确模拟主动脉内的血流动力学环境。因此，入口速度剖面 (IVP) 的选择至关重要；然而，通常采用理想化的配置文件，IVP 对解剖主动脉血流动力学的影响尚不清楚。本研究检查了与 IVP 影响相关的两种情况——使用 (a) 三向 (3D)、贯穿平面 (TP) 或平面 IVP 形式的患者特定数据；(b) 非患者特异性流量波形。从使用患者特定数据的九次模拟中获得的结果表明，所有形式的 IVP 都能够再现 4D 流动磁共振成像观察到的全局流动模式。主要入口撕裂附近的最大速度和时间平均壁剪切应力的差异分别高达 3% 和 6%，而真腔和假腔的压力差异高达 6%。当主要入口撕裂靠近左锁骨下动脉时，在低壁剪切应力区域发现了更显着的变化。使用非患者特异性波形获得的结果明显不同。在整个主动脉中，每搏输出量减少 25% 导致速度和壁剪切应力分别减少 28% 和 35%，而血流波形的形状对预测压力有深远的影响。这项研究的结果表明，3D、TP 和平坦的 IVP 都产生了相当相似的速度和时间平均壁面剪应力结果，但应尽可能使用 TP IVP 以更好地预测压力。在缺乏患者特定速度数据的情况下，应努力获取患者的每搏输出量并相应地调整应用的 IVP。